Impact of renin-angiotensin system inhibitors on mortality and major cardiovascular endpoints in hypertension: A number-needed-to-treat analysis

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Objective To assess the effectiveness of renin-angiotensin aldosterone system (RAAS) inhibitors to prevent all-cause and cardiovascular death, myocardial infarction and stroke in hypertensive patients considering the number needed to treat (NNT). Methods Data from a meta-analysis of 18 prospective, randomized, controlled morbidity-mortality trials (68 343 RAAS inhibitor; 84 543 control) were used to calculate NNTs for the prevention of all-cause and cardiovascular mortality, myocardial infarction, and stroke. Results Angiotensin-converting enzyme (ACE) inhibitors were used in 7 trials and angiotensin receptor blockers (ARBs) in 11 trials. Mean follow-up was 4.3 years. The annual incidence rate of all-cause mortality was 0.0233 in patients randomized to RAAS inhibitors versus 0.0252 in controls (hazard ratio 0.95, 95% confidence interval 0.91 to 0.99). The corresponding median NNT to prevent one death was 113 (2.5-97.5th percentile, 85 to 168) in favor of RAAS inhibitors, which was driven by ACE inhibitors (NNT 67, 2.5-97.5th percentile, 53 to 92) rather than ARBs (NNT 335, 2.5-97.5th percentile, - 4341 to 5076). Results for cardiovascular mortality (NNT 116 for ACE inhibitors and 409 for ARBs, respectively) and myocardial infarction (NNT 80 and 338, respectively) also appeared to be driven by ACE inhibitors. We found a lower NNT for stroke in favor of ARB (NNT 337 and 131, respectively) although this difference was statistically non-significant. Conclusion Among hypertensive patients, ACE inhibitors but not ARBs, substantially reduce all-cause and cardiovascular mortality and myocardial infarction.